1. Field of the Invention
The present invention relates to a film deposition apparatus and a film deposition method using ultra fine particles formed by arc heating method.
2. Description of the Related Art
Conventionally, the film deposition apparatus of the above type is exemplified by the one having gas deposition method applied thereto.
Such a gas deposition apparatus is structured by, for example, a ultra-fine particle generation chamber, a film deposition chamber, and a transfer tube for connection between the ultra-fine particle generation chamber and the film deposition chamber. In the ultra-fine particle generation chamber, arc heating, resistance heating, high-frequency induction heating, laser heating, or the like evaporates materials in inert gas atmosphere. Then, colliding the resulting evaporated materials against the inert gas generates ultra fine particles, each ranging in diameter from a few nm to a few μm. The ultra-fine particle generation chamber is so set as to be higher in pressure than the film deposition chamber. Due to the pressure difference, the ultra fine particles generated in the ultra-fine particle generation chamber are led to the film generation chamber via the transfer tube. Here, an end portion of the transfer tube is placed in the film deposition chamber, and the end portion is nozzle-shaped. From this nozzle, the ultra fine particles are ejected at high speed toward a substrate placed in the film deposition chamber. As such, colliding the ultra fine particles against the substrate leads to any desired pattern in a direct manner. For details, see Japanese Patents No. 2524622, No. 1595398, No. 2632409, and No. 2596434.
Such a gas deposition method has been considered applicable to varying areas such as electrical wiring (see JP-A-5-47771), bump-shaped electrodes (see JP-A-10-140325), and joint members (see JP-A-7-37512).
The ultra fine particles are generated by induction heating, arc heating, resistance heating, or the like. The ultra fine particles made of high melting point materials exemplified by zirconium (Zr) or vanadium (V) may be possibly used as non-evaporating getters due to their specific surface size (see JP-A-2000-208033). For such a high melting point metal, arc heating works effectively.
In a case of forming electrical wiring by gas deposition using silver (Ag) or aluminum (Al) which is not the high melting point material, arc heating works also effectively in view of film deposition at high rate with more evaporation.
For arc heating, usually, as shown in FIG. 5, the ultra-fine particle generation chamber includes an electrode arm, at the tip of which is attached with a tip-pointed rod electrode 101. Then, generally, discharge is caused between the tip of the rod electrode 101 and a material 8 to be evaporated (see JP-A-2000-17427 and Japanese Patent No. 2596434).
Here, in FIG. 5, a reference numeral 13 denotes a carbon-made hearth liner (carbon-made container) having a concave part on which the material 8 is placed. A reference numeral 12 denotes a part where the material 8 is to be melted.
To maintain the stable evaporation of the material 8, the rod electrode 101 is so angled as to form a few tens of degrees in the vertical direction with respect to the material 8.
When the rod electrode 101 is put in an upright position, lengthwise, with respect to the surface of the material 8, the evaporated material 8 tends to adhere to the rod electrode 101. This results in deformation of the tip of the rod electrode 101 which renders evaporation of the material 8 unstable.
Conversely, when the rod electrode 101 is put in a parallel position, lengthwise, with respect to the surface of the material 8, the generated ultra fine particles are blown off in the direction opposite to the rod electrode 101. As a result, the particle smoke, i.e., the ultra-fine particle flow, becomes difficult to be sucked up into the transfer tube located above the material 8.
FIG. 6 is a diagram for illustrating the state of the generated ultra-fine particle smoke, i.e., the ultra-fine particle flow, 14.
In FIG. 6, by putting the rod electrode 101 into a horizontal position from the state shown in FIG. 6, i.e., by putting the rod electrode 101 into a parallel position, lengthwise, with respect to the surface of the material 8, the generated ultra fine particles start being blown off in the direction opposite to the electrode 101, i.e., the direction indicated by an arrow 15. This makes the ultra-fine particle smoke 14 difficult to be sucked up into a transfer tube 3 located above the material 8.
This tendency becomes more noticeable with the higher arc voltage, and with the larger angle of the rod electrode 101 with respect to the vertical direction, i.e., as the rod electrode 101 becomes more parallel, lengthwise, with respect to the surface of the material 8.
Such a phenomenon may be caused by the collision of the flow of the thermoelectron emitted from the rod electrode 101 and the generated ultra-fine particle smoke 14. Such a collision may blow off the ultra fine particles in the direction opposite to the electrode 101.
Therefore, conventionally, to achieve the more efficient leading of the particle smoke 14 to the suction part of the transfer tube, the rod electrode 101 is angled about 30 to 45 degrees with respect to the vertical direction as shown in FIG. 6. In addition, applied is a method for adjusting the arc voltage and the arc current values.